Vehicle active suspension systems require suspension units for the vehicle wheels which incorporate controllable actuators and transducer means for providing information about road wheel experience. The information is supplied to a control system which in turn provides signals for controlling the actuators. Vehicle active suspension systems are described for example in U.S. Pat. No. 4,625,993 and in the patent to be granted on application Ser. No. 747,130, the contents of which are incorporated herein by reference.
It is an object of the invention to provide a vehicle wheel suspension unit comprising an actuator and transducer means responsive to wheel experience which is of improved configuration in respect of the transducer means.
It is an object of the invention to provide a vehicle wheel suspension unit comprising an actuator and a transducer in which the actuator is associated with a suspension spring and the transducer is arranged to be responsive to the actuator loading only.